COP1, an Arabidopsis regulatory gene, encodes a protein with both a zinc-binding motif and a G beta homologous domain

Cell. 1992 Nov 27;71(5):791-801. doi: 10.1016/0092-8674(92)90555-q.


Plant seedling development is capable of following 1 of 2 distinct morphogenic pathways: skotomorphogenesis in darkness and photomorphogenesis in light. Dark-grown Arabidopsis seedlings with recessive mutations at the constitutively photomorphogenic (COP1) locus indicate that the wild-type COP1 protein represses photomorphogenesis in darkness and that light reverses this repressive activity. Using a T-DNA-tagged mutant, we have cloned the COP1 locus. The amino-terminal half of the encoded protein contains a conserved zinc-binding motif, whereas the carboxyl-terminal half contains a domain homologous to the WD-40 repeat motif of G beta proteins. The presence of both a putative DNA-binding motif and a G protein-related domain in a single polypeptide suggests that COP1 may be the first of a new class of regulatory molecules. This novel structure could endow COP1 with the capacity to function as a negative transcriptional regulator capable of direct interaction with components of the G protein signaling pathway.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Arabidopsis / genetics*
  • Arabidopsis / growth & development
  • Base Sequence
  • Cell Differentiation
  • Cloning, Molecular
  • Consensus Sequence
  • GTP-Binding Proteins / genetics*
  • Gene Expression / radiation effects
  • Genes, Plant*
  • Genes, Regulator*
  • Light
  • Microscopy, Electron, Scanning
  • Molecular Sequence Data
  • Oligodeoxyribonucleotides / chemistry
  • Polymerase Chain Reaction
  • RNA, Messenger / genetics
  • Restriction Mapping
  • Sequence Alignment
  • Zinc Fingers*


  • Oligodeoxyribonucleotides
  • RNA, Messenger
  • GTP-Binding Proteins